A music school has budgeted to purchase 3 musical instruments. They plan to purc

Question

A music school has budgeted to purchase 3 musical instruments. They plan to purchase a piano costing $3,000, a guitar costing $550, and a drum set costing $650. The mean cost for a piano is $3,500 with a standard deviation of $2,000. The mean cost for a guitar is $500 with a standard deviation of $250. The mean cost for drums is $950 with a standard deviation of $125. (Enter your answers to two decimal places.)

How many standard deviations above or below the average piano cost is the piano?

How many standard deviations above or below the average guitar cost is the guitar?

How many standard deviations above or below the average drum set cost is the drum set?

Explanation / Answer

For pianos, cost = 3000 , mean = 3500 , s = 2000

z = (cost -mean) / s = ( 3000 - 3500) / 2000 = - 0.25

the cost of the piano is 0.25 standard deviations BELOW average.

For guitars,

cost = 550 , mean = 500 , s = 250

z = (cost -mean) / s = ( 550 - 500) / 250 = 0.25

the cost of the guitar is 0.25 standard deviations ABOVE average.

For drums,

cost = 650 , mean = 950 , s = 125

z = (cost -mean) / s = ( 650 - 950) / 125 = -2.4

the cost of the drum set is 2.4 standard deviations BELOW average.

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.